yade-users team mailing list archive

[mohsen <question291781@xxxxxxxxxxxxxxxxxxxxx>]

Question #291781 on Yade changed:
https://answers.launchpad.net/yade/+question/291781

    Status: Open => Answered

mohsen proposed the following answer:
In the name of god
Hi Geo


> 1)When the confining pressure 10KPa is added, the particles in the packing decrease. Maybe the packing has exploded?
This could be True. by increasing E, stiffness would be larger and leads to lower critical time step (see [1] equation 13). and because of this by decreasing dt the simulation continues! 

>The specimen is compacted and the particles doesn't disappear. It is
defective that the unbalanced force can't <0.01, >increasing the damping
is no use. I increase the max unbalanced force to 0.03, the script can
just continue. But when I >load the deviatoric stress by controlling
strain rate=-0.02, the axial stress is decreasing gradually from 0.8MPa
even to >0.4MPa.(The confining pressure is 0.8MPa.) And when deviatoric
loading, I can see the obviously moving of the particles.

That is right. when you increase stability threshold (from 0.01 to 0.03), in the beginning of loading phase, there would be a decrease in dedicator stress. if you wait after several iterations (depending on your simulation may be from order of 1000) again dedicator stress increases. Therefore:
1- try do your simulation with max unbalanced force=0.01. may this takes along to get 0.01but finally it would reach it
2-  max unbalanced force depends on your material, number and shape of particles, ... .

[1]: https://yade-dem.org/doc/formulation.html

-- 
You received this question notification because your team yade-users is
an answer contact for Yade.